Donor substrate for laser induced thermal imaging, method of laser induced thermal imaging and method of manufacturing an organic light emitting display device using the same

ABSTRACT

A donor substrate, a method of laser induced thermal imaging, and a method of manufacturing an organic light emitting display device are disclosed. In the method of laser induced thermal imaging, a donor substrate is provided to include a base substrate, a light to heat conversion layer, a transfer layer and a functional layer. The functional layer includes a material radiating an infrared light. The donor substrate is laminated to an acceptor substrate. A laser beam is radiated into the donor substrate, thereby forming an organic layer pattern on the acceptor substrate from the transfer layer. A position of the organic layer pattern is observed using an infrared microscope. A laser beam position is adjusted and the donor substrate is separated from the acceptor substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 USC §119 to Korean PatentApplication No. 10-2013-0048537 filed on Apr. 30, 2013 in the KoreanIntellectual Property Office (KIPO), the entire disclosure of which isincorporated herein by reference.

BACKGROUND

1. Field

Example embodiments relate to donor substrates, methods of laser inducedthermal imaging and methods of manufacturing organic light emittingdisplay devices using the same. Particularly, example embodiments relateto donor substrates capable of easily observing a position of atransferred organic layer pattern, methods of laser induced thermalimaging using the same and methods of manufacturing organic lightemitting display devices using the same.

2. Description of the Related Technology

Generally, organic light emitting display devices may include variousorganic layers such as an organic light emitting layer, a hole injectionlayer, an electron transfer layer, etc. In processes for forming theorganic layers of conventional organic light emitting display devices,an ink-jet printing process may use limited materials for forming theorganic layers except the light emitting layer, and it may be necessaryto form an additional structure on a substrate for the ink-jet printingprocess. When using a deposition process for forming organic layers, itmay be difficult to apply the deposition process to the organic lightemitting display device having a relatively large area, because thedeposition process may use a micro-dimensioned metal mask.

Recently, a laser induced thermal imaging process has been developed forforming organic layers of the organic light emitting display device. Inthe conventional laser induced thermal imaging process, a laser beamfrom a laser irradiation apparatus may be converted to a thermal energy,and a transfer layer of a donor substrate may be partially transferredon a display substrate of the organic light emitting display device bythe thermal energy, thereby to form an organic layer pattern. As for theconventional laser induced thermal imaging process, however, theposition of the organic layer pattern may be observed after removing thedonor substrate from an acceptor substrate.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

Some example embodiments provide a donor substrate capable of easilyobserving a position of a transferred organic layer pattern.

Some example embodiments provide a method of laser induced thermalimaging capable of easily observing a position of a transferred organiclayer pattern.

Some example embodiments provide a method of manufacturing an organiclight emitting display device capable of easily observing a position ofa transferred organic layer pattern.

However, objects of example embodiments are not limited to the above,but can be variously expanded without departing from the presentembodiments.

According to example embodiments, there is provided a donor substrateincluding a base substrate, a light to heat conversion layer, a transferlayer and a functional layer. The light to heat conversion layer isdisposed on the base substrate. The transfer layer is disposed on thelight to heat conversion layer. A functional layer is disposed tocontact a surface of the light to heat conversion layer. The functionallayer includes a material radiating an infrared light.

In some example embodiments, the functional layer may include silver(Ag) or a halide having a fluorescent property.

In some example embodiments, the functional layer may be disposedbetween the light to heat conversion layer and the transfer layer.

In some example embodiments, the functional layer may be disposedbetween the light to heat conversion layer and the base substrate.

According to example embodiments, there is provided a method of laserinduced thermal imaging. In the method of laser induced thermal imaging,a donor substrate is provided to include a base substrate, a light toheat conversion layer, a transfer layer and a functional layer. Thefunctional layer includes a material radiating an infrared light. Thedonor substrate is laminated to an acceptor substrate. A laser beam isradiated into the donor substrate, thereby forming an organic layerpattern on the acceptor substrate from the transfer layer. A position ofthe organic layer pattern is observed using an infrared microscope. Alaser beam position is adjusted. The donor substrate is separated fromthe acceptor substrate.

In some example embodiments, observing the position of the organic layerpattern using the infrared microscope may be performed, beforeseparating the donor substrate from the acceptor substrate.

In some example embodiments, a top surface of the acceptor substrate hasa stepped portion.

In some example embodiments, observing the position of the organic layerpattern using the infrared microscope may include observing an infraredradiation difference at the stepped portion of the acceptor substrate.

In some example embodiments, separating the donor substrate from theacceptor substrate may include separating the functional layer from theacceptor substrate.

In some example embodiments, the functional layer may include silver ora halide having a fluorescent property.

In some example embodiments, the laser beam may include a solid-statelaser or a gas-state laser.

According to example embodiments, there is provided a method of laserinduced thermal imaging. In the method of laser induced thermal imaging,a donor substrate is provided to include a base substrate, a light toheat conversion layer, a transfer layer and a functional layer. Thedonor substrate has a first region and a second region. The functionallayer includes a material radiating an infrared light. The donorsubstrate is laminated to an acceptor substrate. A laser beam isradiated into the first region of the donor substrate. A laser beamposition is observed using an infrared microscope. A laser beam positionis adjusted. A laser beam is radiated into the second region of thedonor substrate, thereby forming an organic layer pattern on theacceptor substrate from the transfer layer. The donor substrate isseparated from the acceptor substrate.

According to example embodiments, there is provided a method ofmanufacturing an organic light emitting display device. In the method, adonor substrate is provided to include a base substrate, a light to heatconversion layer, a transfer layer and a functional layer. Thefunctional layer includes a material radiating an infrared light. Adisplay substrate is provided to include a switching device, a firstelectrode and a pixel defining layer. The donor substrate is laminatedto the display substrate. A laser beam is radiated into the donorsubstrate, thereby forming an organic layer pattern on the displaysubstrate from the transfer layer. A position of the organic layerpattern is observed using an infrared microscope. A laser beam positionis adjusted. The donor substrate is separated from the displaysubstrate.

In some example embodiments, observing the position of the organic layerpattern using the infrared microscope may be performed, beforeseparating the donor substrate from the display substrate.

In some example embodiments, the first electrode may have a top surfacesubstantially lower than a top surface of the pixel defining layer, suchthat a stepped portion may be disposed between the first electrode andthe pixel defining layer.

In some example embodiments, observing the position of the organic layerpattern using the infrared microscope may include observing a infraredradiation difference at the stepped portion of the display substrate.

According to example embodiments, a donor substrate may further includea functional layer disposed adjacent to the light to heat conversionlayer. The functional layer may be formed using the fluorescent materialor the ink, such that the functional layer may radiate the infraredlight. When the donor substrate is used in the laser induced thermalimaging, it is possible to inspect a position of a transferred organiclayer pattern by detecting the infrared light from the functional layer.Particularly, when the donor substrate is laminated on an acceptorsubstrate having a stepped portion, it is possible to inspect a positionof the stepped portion by detecting the infrared light.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings. FIGS. 1 to 13 represent non-limiting, example embodiments asdescribed herein:

FIG. 1 is a perspective view illustrating a laser induced thermalimaging apparatus in accordance with some embodiments;

FIG. 2 is a cross-sectional view illustrating a donor substrate forlaser induced thermal imaging in accordance with some embodiments;

FIG. 3 is a cross-sectional view illustrating a donor substrate forlaser induced thermal imaging in accordance with other embodiments;

FIG. 4 is a perspective view illustrating an acceptor substrate in FIG.1;

FIG. 5 is a flow chart illustrating a method of laser induced thermalimaging in accordance with some embodiments;

FIG. 6 is a flow chart illustrating a method of laser induced thermalimaging in accordance with other embodiments; and

FIGS. 7 to 10 are a perspective view and cross-sectional viewsillustrating a method of manufacturing an organic light emitting displaydevice in accordance with some embodiments.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Various example embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exampleembodiments are shown. The present embodiments may, however, be embodiedin many different forms and should not be construed as limited to theexample embodiments set forth herein. Rather, these example embodimentsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the present embodiments to those skilledin the art. In the drawings, the sizes and relative sizes of layers andregions may be exaggerated for clarity. Like numerals refer to likeelements throughout.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are used to distinguish oneelement from another. Thus, a first element discussed below could betermed a second element without departing from the teachings of thepresent embodiments. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent embodiments. As used herein, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which these embodiments belong. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 is a perspective view illustrating a laser induced thermalimaging apparatus in accordance with some embodiments.

Referring to FIG. 1, a laser induced thermal imaging apparatus 100 mayinclude a laser beam source 112, an optical system 114, an infraredmicroscope 122 and a substrate stage 130.

The laser beam source 112 may generate a laser beam. For example, thelaser beam may include a solid-state laser such as a ruby laser, ayttrium-aluminium-garnet (YAG) laser, a yttrium-lithium-fluoride (YLF)laser, etc. or a gas-state laser such as an excimer layer, helium-neonlayer, etc.

The optical system 114 may manipulate the laser beam received from thelaser beam source 112. The optical system 114 may manipulate the laserbeam into a desired shape such as a line beam or a squared beam. Theoptical system 114 may be disposed on an optical path of the laser beam,which is between the laser beam source 112 and the substrate stage 130.

In some example embodiments, the optical system 114 may include ahomogenizer which may homogenize the laser beam. The optical system 114may further include a mirror or a lens which may reflect or refract thelaser beam. For example, the mirror may be a galvano mirror that mayrotate depending on an input voltage. Therefore, a progress direction ofthe laser beam may be adjusted using the mirror or the lens.

In other example embodiments, the optical system 114 may include variouscombinations of optical components such as a condensing lens or apolarizer.

The laser beam source 112 and the optical system 114 may be mounted onthe first guide bar 110. In some example embodiments, the optical system114 may move in a second direction according to the first guide bar 110.Therefore, the laser beam position on the donor substrate 250 may beadjusted in the second direction.

The positions of the laser beam source 112 and the optical system 114may not be limited to FIG. 1. For example, the laser beam source 112 andthe optical system 114 may be arranged in a third directionsubstantially perpendicular to a top surface of the donor substrate 250.In this case, the optical system 114 may not include the mirror.

The infrared microscope 122 may include at least two lenses and a chargecoupled device (CCD). For example, the lenses may include an objectivelens and an ocular to allow a magnified view of the same. The CCD mayhave a sufficient sensitivity to an infrared light. Therefore, theinfrared microscope 122 may observe the infrared light generated fromthe donor substrate 250.

The infrared microscope 122 may be mounted on a second bar 120, whichmay be spaced apart from the first bar 110 in a first direction. In someexample embodiments, the infrared microscope 122 may move in the seconddirection according to the second bar 120. Alternatively, a plurality ofinfrared microscopes 122 may be mounted on the second bar 120, and theplurality of infrared microscopes 122 may be fixed in the seconddirection.

The substrate stage 130 may be a substrate supporter to support andtransport an acceptor substrate 200. The substrate stage 130 may includea base portion 132, a moving portion 134 and a chuck 136. The chuck 136may hold the acceptor substrate 200 to the substrate stage 130, and themoving portion 134 may transport the acceptor substrate 200 in the firstdirection.

The acceptor substrate 200 and the donor substrate 250 may be disposedon the substrate stage 130. The donor substrate 250 may be describedwith reference to FIG. 2 or FIG. 3 as follows. The acceptor substrate200 may be described with reference to FIG. 4 as follows.

The laser induced thermal imaging apparatus 100 may further include acontrol portion (not shown) for controlling the laser beam source 112,the optical system 114 and the substrate stage 130. The laser inducedthermal imaging apparatus 100 may further include a mask disposedbetween the optical system 114 and the donor substrate 250.

FIG. 2 is a cross-sectional view illustrating a donor substrate forlaser induced thermal imaging in accordance with some embodiments.

Referring to FIG. 2, the donor substrate 250 for the laser inducedthermal imaging may include a first base substrate 260, a light to heatconversion layer 270, a functional layer 280, a transfer layer 290, etc.

The first base substrate 260 may include a transparent polymer material.For example, the first base substrate 260 may include a polymer such aspolyethylene terephthalate, polyester, polyacryl, polyepoxy,polyethylene, polystyrene, etc. The first base substrate 260 may have athickness of about 10 μm to about 500 μm. If the first base substrate260 has a thickness below about 10 μm, it is hard to handle the firstbase substrate 260, because the first base substrate 260 may not have aproper mechanical strength. If the first base substrate 260 has athickness above about 500 μm, it is hard to transport the first basesubstrate 260 due to a weight of the first base substrate 260. The firstbase substrate 260 may serve to support components of the donorsubstrate 250.

The light to heat conversion layer 270 may be disposed on the first basesubstrate 260. The light to heat conversion layer 270 may include alight absorption material which may convert the laser beam into athermal energy. In some example embodiments, the light to heatconversion layer 270 may include a metal such as aluminum, silver,molybdenum, chromium, an oxide thereof or a sulfide thereof. In thiscase, the light to heat conversion layer 270 may have a relatively smallthickness of about 10 nm to about 500 nm. In other example embodiments,the light to heat conversion layer 270 may include an organic materialsuch as carbon black or graphite. In this case, the light to heatconversion layer 270 may have a relatively large thickness of about 100nm to about 10 μm. The heat generated in the light to heat conversionlayer 270 may change a bonding strength between the light to heatconversion layer 270 and the transfer layer 290, such that a portion ofthe transfer layer 290 may be transferred to an acceptor substrate witha predetermined shape.

In some example embodiments, the light to heat conversion layer 270 mayfurther include a gas generating material such as pentaerythritetetranitrate (PETN) and trinitrotoluene (TNT). When the light to heatconversion layer 270 absorbs the thermal energy, the gas generatingmaterial may emit a nitrogen gas or a hydrogen gas to provide energy fora transfer step in the laser induced thermal imaging process.

The functional layer 280 may be formed using a material radiating aninfrared light. In some example embodiments, the functional layer 280may include silver (Ag) or a halide having a fluorescent property. Inother example embodiments, the functional layer 280 may be formed usingan ink which can absorb a visible light and can radiate an infraredlight (See KR 2010-0110068).

The transfer layer 290 may be disposed on the functional layer 280. Whenmanufacturing an organic light emitting display device using the donorsubstrate 250, the transfer layer 290 may include a materialsubstantially the same as or substantially similar to that of an organiclayer pattern. That is, the organic layer pattern may be formed on theacceptor substrate from the transfer layer 290 of the donor substrate250. In some example embodiments, the organic layer pattern may includean organic light emitting layer, a hole injection layer, a hole transferlayer, an electron injection layer or an electron transfer layer of theorganic light emitting display device. The organic light emittingdisplay device including a plurality of organic layer patterns may beformed from the transfer layer 290.

A buffer layer (not shown) or an intermediate layer (not shown) may befurther disposed between the transfer layer 290 and the light to heatconversion layer 270.

According to example embodiments, the donor substrate 250 may furtherinclude the functional layer 280 disposed between the light to heatconversion layer 270 and the transfer layer 290. The functional layer280 may be formed using the fluorescent material or the ink, such thatthe functional layer 280 may radiate the infrared light. When the donorsubstrate 250 is used in the laser induced thermal imaging, it ispossible to inspect a position of the transferred organic layer patternby detecting the infrared light from the functional layer 280.Particularly, when the donor substrate 250 is laminated on an acceptorsubstrate 200 having a stepped portion (See FIG. 4), it is possible toinspect a position of the stepped portion by detecting the infraredlight.

FIG. 3 is a cross-sectional view illustrating a donor substrate forlaser induced thermal imaging in accordance with other embodiments. Thedonor substrate 252 may be substantially the same as or substantiallysimilar to the donor substrate 250 described with reference to FIG. 2,except for a position of a functional layer 282. Thus, like referencenumerals refer to like elements, and repetitive explanations thereon maybe omitted herein

Referring to FIG. 3, the donor substrate 252 may include the first basesubstrate 260, the light to heat conversion layer 270, the functionallayer 282 and the transfer layer 290. In some example embodiments, thefunctional layer 282 may include a material substantially the same as orsubstantially similar to that of the functional layer 280 described withreference to FIG. 2.

According to example embodiments, the donor substrate 252 may furtherinclude the functional layer 282 disposed between the light to heatconversion layer 270 and the first base substrate 260. Even thought theposition of the functional layer 282 is changed compared to FIG. 2, itis possible to inspect the position of the transferred organic layerpattern by detecting the infrared light from the functional layer 282while the donor substrate 252 is laminated on the acceptor substrate.

FIG. 4 is a perspective view illustrating an acceptor substrate in FIG.1.

The acceptor substrate 200 may be any substrate to which an organiclayer pattern is transferred. The acceptor substrate 200 may be asubstrate for a semiconductor device, a display device, a touch panel,and the like. The acceptor substrate 200 may include a switchingstructure (not shown) or a semiconductor structure (not shown).

In some example embodiments, the acceptor substrate 200 may include asecond base substrate 210 and a pattern layer 220. The second basesubstrate 210 may have a predetermined flexibility and a predeterminedstrength. The material of the second base substrate 210 may not belimited.

The pattern layer 220 may be disposed on the second base substrate 210and may have a predetermined shape. Therefore, a stepped portion may bedisposed between a top surface of the second base substrate 210 and atop surface of the pattern layer 220. In some example embodiments, thepattern layer 220 may be a pixel defining layer of the display device.In this case, the pixel defining layer may have a shape to surround apixel region of the display device.

The donor substrate 250 (See FIG. 2) may be laminated on a top surfaceof the acceptor substrate 200. That is, the donor substrate 250 may bedisposed such that the transfer layer 290 (See FIG. 2) of the donorsubstrate 250 may directly contact the top surface of the acceptorsubstrate 200.

The donor substrate 250 may have a relatively large flexibility, so thatthe donor substrate 250 may be deformed according to a profile of thetop surface of the acceptor substrate 200. That is, the donor substrate250 may be deformed to have a stepped portion according to the profileof the pattern layer 220.

When a laser beam is radiated into the donor substrate 250, an organiclayer pattern is transferred to the acceptor substrate 200. The steppedportion of the donor substrate 250 may be easily observed by theinfrared microscope 122 (See FIG. 1) due to the infrared light radiatedfrom the functional layer 280 (See FIG. 2). In this case, the edge ofthe stepped portion may be distinguished from other portion, so that aposition of the transferred organic layer pattern may be easilyobserved, while the donor substrate 250 is laminated on the acceptorsubstrate 200. That is, without removing the donor substrate 250 fromthe acceptor substrate 200, it is possible to determine whether or notthe organic layer pattern is properly transferred at a predeterminedposition.

FIG. 5 is a flow chart illustrating a method of laser induced thermalimaging in accordance with some embodiments.

Referring to FIG. 5, a donor substrate 250 (See FIG. 2) including afunctional layer 280 (See FIG. 2) may be prepared (S110). The step ofpreparing the donor substrate 250 may include sequentially forming alight to heat conversion layer 270 (See FIG. 2), the functional layer280 and a transfer layer 290 (See FIG. 2) on a first base substrate 260(See FIG. 2).

The first base substrate 260 may include a transparent polymer material.For example, the first base substrate 260 may include a polymer such aspolyethylene terephthalate, polyester, polyacryl, polyepoxy,polyethylene, polystyrene, etc.

Then, the light to heat conversion layer 270 may be formed on the firstbase substrate 260. For example, the light to heat conversion layer 270may be formed using a metal such as aluminum, silver, molybdenum,chromium, an oxide thereof by a thermal evaporation process, an E-beamevaporation process or a sputtering process. Alternatively, the light toheat conversion layer 270 may be formed using a sulfide thereof or anorganic material such as carbon black or graphite by a roll coatingprocess, a gravure coating process, a spin coating process, a knifecoating process, and the like.

The functional layer 280 may be formed on the light to heat conversionlayer 270 using a material radiating an infrared light. In some exampleembodiments, the functional layer 280 may be formed using silver (Ag) ora halide having a fluorescent property. In other example embodiments,the functional layer 280 may be formed using an ink which can absorb avisible light and can radiate an infrared light (See KR 2010-0110068).The functional layer 280 may be formed by a roll coating process or aspin coating process.

Then, the transfer layer 290 may be formed on the functional layer 280.The transfer layer 290 may include an organic material which may bethermally transferred to an accepter substrate 200. The transfer layer290 may be a single layer structure or a multi layer structure. Thetransfer layer 290 may be formed by an evaporation process, a chemicalvapor deposition (CVD) process or a coating process.

The acceptor substrate 200 (See FIG. 4) having a stepped portion may beprepared (S120). In some example embodiment, the acceptor substrate 200may be a display substrate of a display apparatus. The display substratemay be described with reference to FIG. 7 as follows.

The donor substrate 250 may be laminated on the acceptor substrate 200(S130). After aligning the donor substrate 250 with respect to theacceptor substrate 200, the donor substrate 250 may be laminated on theacceptor substrate 200 by applying a pressure to the donor substrate 250using a pressurizing device. In some example embodiments, thepressurizing device may include a roller, a crown press, and the like.Alternatively, the donor substrate 250 may be adhered to the acceptorsubstrate 200 by applying a pressure to the donor substrate 250 using agas nozzle.

The acceptor substrate 200 may include the stepped portion and the donorsubstrate 250 may have a relatively large flexibility, so that the donorsubstrate 250 may be deformed according to a profile of the steppedportion of the acceptor substrate 200. That is, the donor substrate 250laminated on the acceptor substrate 200 also may have a stepped portion.

Then, a laser beam may be radiated on the donor substrate 250, so thatan organic layer pattern is transferred on the acceptor substrate 200(S140).

The laser beam may be radiated in a region of the donor substrate 250where the organic layer pattern is transferred. The laser beam from thelaser beam source 112 of the laser induced thermal imaging apparatus 100(See FIG. 1) may pass through the optical system 114, thereby radiatingthe donor substrate 250.

In the region where the laser beam is radiated, a bonding strengthbetween the transfer layer 290 and the acceptor substrate 200 may besubstantially larger than a bonding strength between the transfer layer290 and the functional layer 280. Therefore, the organic layer patternmay be transferred on the acceptor substrate 200 with a predeterminedshape. The laser beam may have a relatively high resolution, so that theorganic layer pattern may be transferred precisely.

A position of the laser beam radiation and a position of the organiclayer pattern may be inspected by an infrared microscope 122 (S150).

The infrared microscope 122 may include at least two lenses and a chargecoupled device (CCD). For example, the lenses may include an objectivelens and an ocular to allow a magnified view of the same. The CCD mayhave a sufficient sensitivity to an infrared light. Therefore, theinfrared microscope 122 may observe the infrared light generated fromthe donor substrate 250.

Particularly, the donor substrate 250 may be laminated on the acceptorsubstrate 200 to have the stepped portion, the stepped portion may beeasily observed by the infrared microscope 122. That is, the steppedportion of the donor substrate 250 may be pressurized in the laminationprocess (S130) and may be exposed to the laser beam (S140), so that theinfrared light radiated from the stepped portion of the donor substrate250 (that is, the functional layer 280) may be distinguished from otherinfrared light radiated from other portion of the donor substrate 250.Therefore, without removing the donor substrate 250 from the acceptorsubstrate 200, it is possible to observe the position of the laser beamradiation and the position of the organic layer pattern.

The laser beam position may be adjusted depending on the result ofobservation (S160).

The position of the laser beam radiation may be adjusted according tothe position of the organic layer pattern which is observed in thepreceding step (S150). For example, the positions of the laser beamsource 112, the optical system 114 and the substrate stage 130 may beadjusted. Alternatively, the mirror or the lens in the optical system114 may be controlled to change the position of the laser beamradiation. Therefore, by adjusting the laser beam position, the positionof the organic layer pattern which is formed later may be adjusted. Theadjusted laser beam position may be applied to other donor substrate 250after that time.

The donor substrate 250 may be separated from the acceptor substrate 200(S170).

The donor substrate 250 may be peeled off from the acceptor substrate200, after forming the organic layer pattern on the acceptor substrate200. In this case, an inert gas such as a nitrogen gas, an argon gas,and the like may be sprayed between the acceptor substrate 200 and thedonor substrate 250 to promote the separation between the donorsubstrate 250 and the acceptor substrate 200.

The preceding steps (S140 to S170) may be performed about other acceptorsubstrate 200 and other donor substrate 250, repeatedly. In the step ofS160, the laser beam position may be adjusted, so that the position ofthe organic layer pattern may be properly arranged.

According to example embodiments, the donor substrate 250 may belaminated on the acceptor substrate 250 to have the stepped portion. Thestepped portion of the donor substrate 250 may be easily observed by theinfrared microscope 122 (See FIG. 1) due to the infrared light radiatedfrom the functional layer 280 (See FIG. 2). In this case, the edge ofthe stepped portion may be distinguished from other portion, so that theposition of the transferred organic layer pattern may be easilyobserved, while the donor substrate 250 is laminated on the acceptorsubstrate 200.

FIG. 6 is a flow chart illustrating a method of laser induced thermalimaging in accordance with some embodiments. The method of laser inducedthermal imaging may include steps substantially the same as orsubstantially similar to those of the method of laser induced thermalimaging described with reference to FIG. 5.

Referring to FIG. 6, a donor substrate 250 (See FIG. 2) including afunctional layer 280 (See FIG. 2) may be prepared (S210). In someexample embodiments, the donor substrate 250 may be divided into a firstregion and a second region.

An acceptor substrate 200 having a stepped portion may be prepared(S220). For example, the acceptor substrate 200 may be a displaysubstrate of a display device. The acceptor substrate 200 may be dividedinto a third region and a fourth region corresponding to the firstregion and the second region of the donor substrate 250, respectively.For example, the third region may be a display region where the pixel ofthe display device is disposed, and the fourth region may be a testregion for observing a position of a laser beam. The stepped portion maybe arranged regularly and repeatedly in the third region and the fourthregion.

Then, the donor substrate 250 may be laminated on the acceptor substrate200 (S230).

A laser beam may be radiated in the first region of the donor substrate250 (S240).

Then, a position of the laser beam radiation may be inspected by aninfrared microscope 122 (S250).

The laser beam position may be adjusted depending on the result ofobservation (S260).

A laser beam may be radiated in the second region of the donor substrate250 to form an organic layer pattern in the third region of the acceptorsubstrate 200 (S240). The laser beam position may be adjusted in thepreceding step (S260), so that the laser beam may be properly radiatedin the second region of the donor substrate 250. Therefore, the organiclayer pattern may be arranged in a predetermined position.

The donor substrate 250 may be separated from the acceptor substrate 200(S280).

According to example embodiments, the donor substrate 250 may belaminated on the acceptor substrate 250 to have the stepped portion. Thestepped portion of the donor substrate 250 may be easily observed by theinfrared microscope 122 (See FIG. 1) due to the infrared light radiatedfrom the functional layer 280 (See FIG. 2). In this case, the edge ofthe stepped portion may be distinguished from other portion, so that theposition of the transferred organic layer pattern may be easilyobserved, while the donor substrate 250 is laminated on the acceptorsubstrate 200.

FIGS. 7 to 10 are a perspective view and cross-sectional viewsillustrating a method of manufacturing an organic light emitting displaydevice in accordance with some embodiments.

Referring to FIG. 7, a display substrate 300 may be prepared to includea first electrode 370 and a pixel defining layer 375.

In some example embodiments, the display substrate 300 may include afirst substrate 310, a switching structure, insulation layers, the firstelectrode 370, the pixel defining layer 375, and the like.

The first substrate 310 may include a transparent insulation substrate.For example, the first substrate 310 may include a glass substrate, aquartz substrate, a transparent polymer substrate, and the like. Inother example embodiments, the first substrate 310 may be a flexiblesubstrate.

When the organic light emitting display device has an active matrixtype, the switching structure may be formed on the first substrate 310.In some example embodiments, the switching structure may include aswitching device, at least one insulation layer, a contact, a pad, aplug, etc. Here, the switching device may include a thin film transistor(TFT), an oxide semiconductor device, etc.

When the switching device in the switching structure includes the thinfilm transistor, the switching device may be obtained by forming asemiconductor layer 330, a gate electrode 352, a source electrode 354, adrain electrode 356, etc.

In some example embodiments, the semiconductor layer 330 may be disposedon the first substrate 310, and the semiconductor layer 330 may bedivided into a source region 334, a drain region 336 and a channelregion 332 through an ion implantation process. Then, a gate insulationlayer 340 may be disposed to electrically isolate the semiconductorlayer 330.

A gate electrode 352 may be disposed on the gate insulation layer 340,and then a first insulation layer 360 may be disposed on the gateinsulation layer 340 and the gate electrode 352.

The source electrode 354 and the drain electrode 356 may be disposedthrough the gate insulation layer 340 and the first insulation layer 360to contact the source and the drain regions 334 and 336, respectively. Agate signal may be applied to the gate electrode 352 and a data signalmay be applied to the source electrode 354. Then, a second insulationlayer 360 may be disposed to electrically isolate the source electrode354 and the drain electrode 356.

In the organic light emitting display device illustrated in FIG. 7, theswitching device including the thin film transistor may have a top gateconfiguration in which the gate electrode 352 may be disposed over thesemiconductor layer 330, however, the configuration of the switchingdevice may not be limited thereto. For example, the switching device mayhave a bottom gate configuration in which a gate electrode may bedisposed under the semiconductor layer.

A second insulation layer 365 may be disposed on the first insulationlayer 360 to substantially cover the source electrode 354 and the drainelectrode 356. In some example embodiments, the second insulation layer365 may have a substantially flat surface obtained by a planarizationprocess, for example, a chemical mechanical polishing (CMP) process, anetch-back process, etc.

The first electrode 370 may be formed on the switching structure, and apixel defining layer 375 may be formed in a region on the switchingstructure where the first electrode 370 is not positioned.

In some example embodiments, the first electrode 370 may serve as ananode for providing holes into a light emitting structure. Depending onan emission type of the organic light emitting display device, the firstelectrode 370 may be a transparent electrode or a semi-transparentelectrode. For example, the first electrode 370 may be formed using atransparent conductive material such as indium tin oxide (ITO), zinc tinoxide (ZTO), indium zinc oxide (IZO), zinc oxide (ZnOx), tin oxide(SnOx), gallium oxide (GaOx), etc.

In some example embodiments, the pixel defining layer 375 may be formedusing an insulation material. The pixel defining layer 375 may have athickness substantially larger than that of the first electrode 375.Therefore, a stepped portion 372 may be disposed between a top surfaceof the pixel defining layer 375 and a top surface of the first electrode370.

Referring to FIG. 8, a donor substrate 250 may be laminated on thedisplay substrate 300.

The donor substrate 250 may be substantially the same as orsubstantially similar to the donor substrate 250 described withreference to FIG. 2.

After aligning the donor substrate 250 with respect to the displaysubstrate 300, the donor substrate 250 may be laminated on the displaysubstrate 300 by applying a pressure to the donor substrate 250 using apressurizing device. In some example embodiments, the pressurizingdevice may include a roller, a crown press, and the like. Alternatively,the donor substrate 250 may be adhered to the display substrate 300 byapplying a pressure to the donor substrate 250 using a gas nozzle.

The display substrate 300 may include the stepped portion 372 and thedonor substrate 250 may have a relatively large flexibility, so that thedonor substrate 250 may be deformed according to a profile of thestepped portion 372 of the display substrate 300. That is, the donorsubstrate 250 laminated on the display substrate 300 also may have astepped portion.

Referring to FIG. 9, a laser beam may be radiated on the donor substrate250.

The laser beam may be radiated, such that an organic layer pattern 380may be transferred from the transfer layer 290 of the donor substrate250 onto the display substrate 300.

The organic layer pattern 380 (see FIG. 10) may be formed from thetransfer layer 290 at a pressure below about 10⁻² Torr. The organiclayer pattern 380 may be formed in a vacuum chamber, so that pollutionsof the display substrate 300 and the organic layer pattern 380 may beprevented in a formation of the organic layer pattern 380. As a result,a life time of the organic light emitting display device including theorganic layer pattern 380 may be enlarged.

In some example embodiments, the organic layer pattern 380 may be formedin an atmosphere containing an inert gas. For example, the atmospheremay include the inert gas and water vapor, or the inert gas and anoxygen gas (O₂). For example, the inert gas may include a nitrogen (N₂)gas and/or an argon (Ar) gas, and a concentration of water vapor in theatmosphere containing the inert gas may be below about 10 ppm.Alternatively, a concentration of oxygen gas (O₂) in the atmospherecontaining the inert gas may be below about 50 ppm. A pollution of theorganic layer pattern 380 may be prevented by controlling concentrationsof water vapor and oxygen gas.

Then, a position of the laser beam radiation and a position of theorganic layer pattern 380 may be inspected by an infrared microscope 122(See FIG. 1)

The infrared microscope 122 may observe the infrared light generatedfrom the functional layer 280 of the donor substrate 250. Particularly,the donor substrate 250 may be laminated on the display substrate 300 tohave the stepped portion, the stepped portion may be easily observed bythe infrared microscope 122. That is, the stepped portion of the donorsubstrate 250 may be pressurized in the lamination process and may beexposed to the laser beam, so that the infrared light radiated from thestepped portion of the donor substrate 250 may be distinguished fromother infrared light radiated from other portion of the donor substrate250. Therefore, without removing the donor substrate 250 from thedisplay substrate 300, it is possible to observe the position of thelaser radiation and the position of the organic layer pattern 380.

Then, the laser beam position may be adjusted depending on the result ofobservation.

Referring to FIG. 10, donor substrate 250 may be separated from thedisplay substrate 300.

The donor substrate 250 may be peeled off from the display substrate300, after forming the organic layer pattern on the display substrate300. In this case, an inert gas such as a nitrogen gas, an argon gas,and the like may be sprayed between the display substrate 300 and thedonor substrate 250 to promote the separation between the donorsubstrate 250 and the display substrate 300.

The method of manufacturing the organic light emitting display devicemay use the donor substrate 250 described with reference to FIG. 2, thepresent embodiments may not be limited thereto. For example, the methodof manufacturing the organic light emitting display device may use thedonor substrate 252 described with reference to FIG. 3.

In some example embodiments, the organic layer pattern 380 may be anorganic light emitting layer, however the present embodiments may not belimited thereto. For example, the organic layer pattern 380 may be ahole injection layer (HIL), a hole transport layer (HTL), an electroninjection layer (EIL), an electron transport layer (ETL) or a colorfilter layer.

According to example embodiments, the donor substrate 250 including thefunctional layer 280 containing the material radiating an infrared lightmay be used to perform the laser induced thermal imaging, therebyforming the organic layer pattern 380. Therefore, the position of theorganic layer pattern may be easily observed, before the donor substrate250 is separated from the display substrate 300.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in the example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent embodiments. Accordingly, all such modifications are intended tobe included within the scope of the present embodiments as defined inthe claims. Therefore, it is to be understood that the foregoing isillustrative of various example embodiments and is not to be construedas limited to the specific example embodiments disclosed, and thatmodifications to the disclosed example embodiments, as well as otherexample embodiments, are intended to be included within the scope of theappended claims.

What is claimed is:
 1. A method of laser induced thermal imaging,comprising providing a donor substrate including a base substrate, alight to heat conversion layer, a transfer layer and a functional layer,the functional layer including a material radiating an infrared light;laminating the donor substrate to an acceptor substrate; radiating alaser beam into the donor substrate, thereby forming an organic layerpattern on the acceptor substrate from the transfer layer; observing aposition of the organic layer pattern using an infrared microscope;adjusting a laser beam position; and separating the donor substrate fromthe acceptor substrate.
 2. The method of claim 1, wherein observing theposition of the organic layer pattern using the infrared microscope isperformed before separating the donor substrate from the acceptorsubstrate.
 3. The method of claim 1, wherein a top surface of theacceptor substrate has a stepped portion.
 4. The method of claim 3,wherein observing the position of the organic layer pattern using theinfrared microscope includes observing an infrared radiation differenceat the stepped portion of the acceptor substrate.
 5. The method of claim1, wherein separating the donor substrate from the acceptor substrateincludes separating the functional layer from the acceptor substrate. 6.The method of claim 1, wherein the functional layer includes silver or ahalide having a fluorescent property.
 7. The method of claim 1, whereinthe laser beam includes a solid-state laser or a gas-state laser.
 8. Amethod of laser induced thermal imaging, comprising providing a donorsubstrate including a base substrate, a light to heat conversion layer,a transfer layer and a functional layer, the donor substrate having afirst region and a second region, the functional layer including amaterial radiating an infrared light; laminating the donor substrate toan acceptor substrate; radiating a laser beam into the first region ofthe donor substrate observing a laser beam position using an infraredmicroscope; adjust the laser beam position; radiating the laser beaminto the second region of the donor substrate, thereby forming anorganic layer pattern on the acceptor substrate from the transfer layer;and separating the donor substrate from the acceptor substrate.
 9. Themethod of claim 8, wherein the functional layer includes silver or ahalide having a fluorescent property.
 10. The method of claim 8, whereinthe laser beam includes a solid-state laser or a gas-state laser.
 11. Amethod of manufacturing an organic light emitting display device,comprising providing a donor substrate including a base substrate, alight to heat conversion layer, a transfer layer and a functional layer,the functional layer including a material radiating an infrared light;providing a display substrate including a switching device, a firstelectrode and a pixel defining layer; laminating the donor substrate tothe display substrate; radiating a laser beam into the donor substrate,thereby forming an organic layer pattern on the display substrate fromthe transfer layer; observing a position of the organic layer patternusing an infrared microscope; adjusting a laser beam position; andseparating the donor substrate from the display substrate.
 12. Themethod of claim 11, wherein the functional layer includes silver or ahalide having a fluorescent property.
 13. The method of claim 11,wherein the laser beam includes a solid-state laser or a gas-statelaser.
 14. The method of claim 11, wherein observing the position of theorganic layer pattern using the infrared microscope is performed, beforeseparating the donor substrate from the display substrate.
 15. Themethod of claim 11, wherein the first electrode has a top surfacesubstantially lower than a top surface of the pixel defining layer, suchthat a stepped portion is disposed between the first electrode and thepixel defining layer.
 16. The method of claim 11, wherein observing theposition of the organic layer pattern using the infrared microscopeincludes observing an infrared radiation difference at the steppedportion of the display substrate.